For those that are curious? 33s (285/70/17 MTZ) do fit (just) under a challenger with 30P offset kings rims. With some trimming of the mudflaps and plastic inner guards (rear) they clear without rubbing.
They are awsome offroad, however they do have their down sides. They definitely know the gearing around even compared to my my 32s. As such the fuel effciency and performance suffer dramatically (especially of you need to tow as I do).
Fortunely I am lucky enough to be able to run 2 sets of rims so it looks like I'll stick with 32s for general use and highway towing and 33s for off road stuff.
For some reason my PC won't let me post the pics? Will try again later.